On Mon, Aug 24, 2020 at 01:20:46PM -0700, James Bottomley wrote: > On Mon, 2020-08-24 at 22:44 +0300, Jarkko Sakkinen wrote: > > On Fri, Aug 21, 2020 at 04:38:47PM -0300, Jason Gunthorpe wrote: > > > On Thu, Aug 20, 2020 at 09:14:44AM -0700, James Bottomley wrote: > > > > > > > > eg we can't do it because we can't access /dev/tpm for > > > > > permissions or > > > > > something. > > > > > > > > I already said that: we can't it's root.root 0600 currently. All > > > > the TSSs seem to change at least /dev/tpmrm to tpm.tpm 0660 but > > > > we can't do that in the kernel because there's no fixed tpm > > > > uid/gid. > > > > > > Permissions is a pretty good reason to add a sysfs file. > > > > > > Jason > > > > I'm not sure why suid/sgid utility to read pcrs would be worse. > > We don't do root running or suid/sgid binaries any more because they're > exceptional security risks. That's why both TSSs for TPM 2.0 change > the device ownership. For Trousers and TPM 1.2 we used to run the > daemon as root until we started getting CVEs about it. > > James OK, then a binary blob for pcrs would be sufficient. /Jarkko
